Joe Kaeser, chief executive officer of Siemens.
Photograph: David Levene for the Guardian

Global workforces will fall as the next industrial revolution gets under way, the head of one of Germany’s biggest firms has warned, unless workers are retrained with new skills.

Joe Kaeser, global chief executive of the engineering giant Siemens, said up to almost a third of jobs could be lost as the transition from combustion engines to electric cars takes place over the next decade, in what will be “one of the single most important transformations of all time”.

Speaking over the weekend at the Goodwood Festival of Speed, Kaeser said it would be a key challenge for industry leaders to build the car of the future responsibly and get the transformation right, because ultimately many traditional roles will disappear in the short-term.

“It may cause quite a dip in employment, because if you have 20-30 less value chain, then … you have 20%-30% fewer jobs. That is how it has been in the first three industrial revolutions. There has always been a significant change in employment. And then by enabling growth, it actually turned out that more jobs were created. Higher growth was achieved and obviously more people moved out of poverty and had better lives.

“So the first three worked very well and now we’re on the verge of the fourth industrial revolution which will obviously affect manufacturing massively as it accounts for 70% of global GDP.”

Kaesar said it would be up to governments and business to find a solution to the challenges that advances in technology would create, including the retraining of workers whose skills would no longer be relevant.

“The social and economic impact of digitalisation is going to be massive. The least efficient part of the value chain, the middle man, will be cut out. Unfortunately the least efficient part of the value chain is human beings so someone has to do something about the fall out,” he said.

“Preferably governments and business would retrain together. Governments need to set the framework and the private sector needs to fill it with content.”

Siemens, which employs more than 370,000 people globally and 15,000 in the UK, is already spending €500m a year on retraining and qualifications, with plans to invest more, Kaeser said.

Earlier this year Siemens announced plans to invest £200m and create hundreds of jobs in a new UK train factory in Goole, east Yorkshire, to service contracts including HS2 and London Underground. The Munich-based firm has had British operations for more than 170 years and currently operates 14 factories serving local demand in the UK, which is Siemens’ fourth largest market behind the US, Germany and China.

It has also chosen Hull as its European and global hub for renewable energy, making wind turbines.

Kaeser said he was satisfied that Theresa May was seeking a practical outcome in Brexit negotiations, and that Siemens remained committed to the UK. He said the German firm was early and fast to seek dialogue with the UK government a couple of weeks after the referendum.

“From what I think I see, the perception is that the government and the prime minister are trying to find a way to make it work. You look for the 70/30 solution, so you try to get 70% right. You’re still missing 30%, but you get something done. If you wait for 100% it might never get done, because who gets 100%?” he said.

“It is important that government provides a view on what they’re trying to achieve and then we can make up our minds on what that means for us. We are reasonably satisfied with the dialogue we have with the government and the political leadership.”

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Kaeser, who met Donald Trump in Davos in January, said he had been surprised and alarmed by the pace of the escalating trade tensions between the US and its major trading partners.

“If you start something and let it out of the box, it’s often hard to get it back in. That’s what I’m most concerned about. [It could lead to] nationalism and protectionism.

“It should be a concern for every responsible citizen of this planet. How do we avoid the further splitting of our societies?”

Kaeser said trade wars had no place in the digital future, where data flowed freely and there were no boundaries.

New relationship with EU will secure millions of jobs – Theresa May

Britain’s new relationship with the EU will secure millions of aviation jobs and strengthen Britain’s position as a leading aerospace nation, Theresa May will say on Monday.

Opening the 2018 Farnborough International Airshow, the prime minister will say the UK is at the forefront of civil aviation, as she announces £343m of research funding to support new technology such as greener planes.

“I want us to build on [our leading position in aerospace] and ensure not only that we retain our prominence, but that in an increasingly competitive industry we make the most of the opportunities that lie ahead.”

A spokesman for Airbus, the European aerospace giant that has publicly called for more clarity on Brexit, responded: “We welcome the commitment and personal endorsement of our sector from the prime minister and this is a reflection of the importance of aerospace in the UK.”

•This article was amended on 16 July 2018 to clarify the impact on jobs of the next industrial revolution in the first paragraph